Fix release workflow missing checkout step

The create-release job needs a git repo for gh release create
--generate-notes to work. Add actions/checkout before downloading
artifacts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: JAORMX

.github/workflows/release.yaml

@@ -65,6 +65,9 @@ jobs:
     runs-on: ubuntu-latest
     needs: build-artifacts
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
       - name: Download all artifacts
         uses: actions/download-artifact@v7
         with: